Here are a few additional resources if you are looking for more critical game theory:
Independently authored by a self-described game developer and consultant, this blog provides a good example of what a critical investment in games could look like. His site is multimodal, featuring articles as well as some audio interviews. I particularly found his article series on story telling interesting because it suggested a system with which we could start to break down the plot of games.
An open-access, peer-reviewed journal on gaming. There are many excellent articles on topics from design to education to critical study.
Gee, James Paul. "Learning and Identity: What Does It Mean to Be a Half-Elf?." What Video Games Have to Teach Us About Learning and Literacy. Second Edition: Revised and Updated Edition. Macmillan, 2007. Print.
In the second chapter of his book, Gee describes three forms of identity at play in games: the player, the character, and the relationship between the player and character. This could help with analysis of characters in videogames.
With a greater focus on classic games and systems, Loading... is another excellent gaming journal that moves beyond traditional academic papers.